Intravenous Regeneration-associated Cell Transplantation Enhances Tissue Recovery in Mice with Acute Ischemic Stroke.

Previously, we reported that transplantation of regeneration-associated cells (RACs) via the ipsilateral external carotid artery reduced stroke volume in mice with permanent occlusion of the middle cerebral artery (MCA). However, intracarotid arterial transplantation is invasive and requires skill, and severe complications may occur, such as thromboembolism, infection, and decreased cerebral blood flow. This study aimed to investigate the efficacy of intravenous injection of RACs in reducing stroke volume and increasing anti-inflammatory and angiogenic factors in mice with focal cerebral ischemia.

Correlation between Phase-difference-enhanced MR Imaging and Amyloid Positron Emission Tomography: A Study on Alzheimer's Disease Patients and Normal Controls.

Purpose: While amyloid-β deposition in the cerebral cortex for Alzheimer's disease (AD) is often evaluated by amyloid positron emission tomography (PET), amyloid-β-related iron can be detected using phase difference enhanced (PADRE) imaging; however, no study has validated the association between PADRE imaging and amyloid PET. This study investigated whether the degree of hypointense areas on PADRE imaging correlated with the uptake of amyloid PET.

Methods: PADRE imaging and amyloid PET were performed in 8 patients with AD and 10 age-matched normal controls.

Multiple Cerebral Infarctions Accompanied by Subcortical and Subarachnoid Hemorrhaging in Bilateral Border Zone Areas in a Patient with Eosinophilic Granulomatosis with Polyangiitis.

Eosinophilic granulomatosis with polyangiitis (EGPA) is often associated with peripheral neuropathy, but reports of central nervous system involvement are quite rare. We herein report a patient with EGPA first identified as having hypereosinophilia who later developed asthma, eosinophilic otitis media, sinusitis, and hemorrhagic colitis. She subsequently developed hemiparesis.

Prevalence and Risk Factors of Silent Brain Infarction in Patients with Aortic Stenosis.

Introduction: Silent brain infarction (SBI) is an independent risk factor for subsequent symptomatic stroke in the general population. Although aortic stenosis (AS) is also known to be associated with an increased risk of future symptomatic stroke, little is known regarding the prevalence and risk factors for SBI in patients with AS.

Methods: The study population comprised 83 patients with severe AS with no history of stroke or transient ischemic attack and paralysis or sensory impairment (mean age 75 ± 7 years).

A Case of Creutzfeldt-Jakob Disease with Stroke-Like Onset.

Creutzfeldt-Jakob disease (CJD) is a prion disease characterized by rapidly progressive dementia that is often followed by behavioral disturbances, ataxia, myoclonus, and akinetic mutism. The initial symptoms of CJD reportedly vary, but the onset is usually gradual. Here, we report a case of CJD with a sudden, stroke-like onset of right hemiparesis to alert readers that CJD can mimic a stroke during its early stage.

Paradoxical Brain Embolism Caused by Isolated Pulmonary Arteriovenous Fistula Successfully Treated with Recombinant Tissue Plasminogen Activator.

Pulmonary arteriovenous fistula (PAVF), a vessel malformation connecting the pulmonary circulation to the systemic circulation while bypassing the pulmonary capillaries, can cause paradoxical cerebral infarction. It is often associated with hereditary hemorrhagic telangiectasia (HHT), a genetic disease characterized by multiple dermal, mucosal, and visceral telangiectasia causing recurrent bleeding. Paradoxical cerebral embolism caused by PAVF without HHT is rare.

Rivaroxaban Promotes Reduction of Embolus Size within Cerebrocortical Microvessels in a Mouse Model of Embolic Stroke.

Previous reports have suggested that direct oral anticoagulants exert a prothrombolytic effect against intracardiac thrombi. We hypothesized that these anticoagulants may also help recanalize occluded intracranial arteries via prothrombolytic effects. In this study, we evaluated the effects of rivaroxaban, a direct oral anticoagulant, on fibrin emboli within the cerebrocortical microvessels in a mouse model of embolic stroke.

Amyloid deposition and CBF patterns predict conversion of mild cognitive impairment to dementia.

Mild cognitive impairment (MCI) can include the transition from a normal state to dementia. To explore biomarkers for the development of dementia, we performed an 18-month follow-up study in 28 patients with amnestic MCI. Amyloid deposition was examined using PiB PET, and cerebral blood flow (CBF) was examined using SPECT.

Neuroprotective Role of Astroglia in Parkinson Disease by Reducing Oxidative Stress Through Dopamine-Induced Activation of Pentose-Phosphate Pathway.

Oxidative stress plays an important role in the onset and progression of Parkinson disease. Although released dopamine at the synaptic terminal is mostly reabsorbed by dopaminergic neurons, some dopamine is presumably taken up by astroglia. This study examined the dopamine-induced astroglial protective function through the activation of the pentose-phosphate pathway (PPP) to reduce reactive oxygen species (ROS).

Diameter of fluorescent microspheres determines their distribution throughout the cortical watershed area in mice.

A hemodynamic mechanism has long been assumed to play an important role in watershed infarction. In recent years, however, clinical evidence has indicated that an embolic mechanism is involved. The mechanism by which emboli are trapped preferentially in watershed areas remains unclear.

A possible role of microglia-derived nitric oxide by lipopolysaccharide in activation of astroglial pentose-phosphate pathway via the Keap1/Nrf2 system.

Background: Toll-like receptor 4 (TLR4) plays a pivotal role in the pathophysiology of stroke-induced inflammation. Both astroglia and microglia express TLR4, and endogenous ligands produced in the ischemic brain induce inflammatory responses. Reactive oxygen species (ROS), nitric oxide (NO), and inflammatory cytokines produced by TLR4 activation play harmful roles in neuronal damage after stroke.

Ipsilateral Facial Tactile Hypesthesia in a Patient with Lateral Medullary Syndrome.

Background: Various sensory impairments have been reported in patients with lateral medullary syndrome, also known as Wallenberg syndrome. The typical sensory impairments experienced by patients with this condition are ipsilateral facial and contralateral trunk and limb thermal hypesthesia and hypoalgesia. Tactile (light touch) sensation is not generally diminished.

Cellular origin and regulation of D- and L-serine in in vitro and in vivo models of cerebral ischemia.

D-Serine is known to be essential for the activation of the N-methyl-D-aspartate (NMDA) receptor in the excitation of glutamatergic neurons, which have critical roles in long-term potentiation and memory formation. D-Serine is also thought to be involved in NMDA receptor-mediated neurotoxicity. The deletion of serine racemase (SRR), which synthesizes D-serine from L-serine, was recently reported to improve ischemic damage in mouse middle cerebral artery occlusion model.

Roles and regulation of ketogenesis in cultured astroglia and neurons under hypoxia and hypoglycemia.

Exogenous ketone bodies (KBs), acetoacetate (AA), and β-hydroxybutyrate (BHB) act as alternative energy substrates in neural cells under starvation. The present study examined the endogenous ketogenic capacity of astroglia under hypoxia with/without glucose and the possible roles of KBs in neuronal energy metabolism. Cultured neurons and astroglia were prepared from Sprague-Dawley rats.

Fatal intracranial hemorrhage after intravenous thrombolytic therapy for acute ischemic stroke associated with cancer-related nonbacterial thrombotic endocarditis.

Nonbacterial thrombotic endocarditis (NBTE) is associated with hypercoagulability in patients with inflammatory states such as cancer and autoimmune diseases. Cardiac vegetations caused by NBTE often lead to life-threatening systemic thromboembolism that most frequently affects the brain, spleen, and kidneys. A 54-year-old woman diagnosed with ovarian cancer suddenly developed back pain and left hemiparesis.

Progranulin deficiency promotes post-ischemic blood-brain barrier disruption.

Loss-of-function mutations of progranulin (PGRN) have been linked to frontotemporal dementia, but little is known about the effects of PGRN deficiency on the brain in health and disease. PGRN has been implicated in neurovascular development, inflammation, and Wnt signaling, a pathway involved in the formation of the blood-brain barrier (BBB). Because BBB alterations and inflammation contribute to ischemic brain injury, we examined the role of PGRN in the brain damage produced by ischemia-reperfusion.

Lipoprotein receptor-related protein-6 protects the brain from ischemic injury.

Background And Purpose: Loss-of-function mutations of the lipoprotein receptor-related protein-6 (LRP6), a coreceptor in the Wingless-related integration site-β-catenin prosurvival pathway, have been implicated in myocardial ischemia and neurodegeneration. However, it remains to be established whether LRP6 is also involved in ischemic brain injury. We used LRP6+/- mice to examine the role of this receptor in the mechanisms of focal cerebral ischemia.

Purinergic signaling induces cyclooxygenase-1-dependent prostanoid synthesis in microglia: roles in the outcome of excitotoxic brain injury.

Cyclooxygenases (COX) are prostanoid synthesizing enzymes constitutively expressed in the brain that contribute to excitotoxic neuronal cell death. While the neurotoxic role of COX-2 is well established and has been linked to prostaglandin E(2) synthesis, the role of COX-1 is not clearly understood. In a model of N-Methyl-D-aspartic acid (NMDA) induced excitotoxicity in the mouse cerebral cortex we found a distinctive temporal profile of COX-1 and COX-2 activation where COX-1, located in microglia, is responsible for the early phase of prostaglandin E(2) synthesis (10 minutes after NMDA), while both COX-1 and COX-2 contribute to the second phase (3-24 hours after NMDA).

Key role of CD36 in Toll-like receptor 2 signaling in cerebral ischemia.

Background And Purpose: Toll-like receptors (TLRs) and the scavenger receptor CD36 are key molecular sensors for the innate immune response to invading pathogens. However, these receptors may also recognize endogenous "danger signals" generated during brain injury, such as cerebral ischemia, and trigger a maladaptive inflammatory reaction. Indeed, CD36 and TLR2 and 4 are involved in the inflammation and related tissue damage caused by brain ischemia.

Brain dendritic cells in ischemic stroke: time course, activation state, and origin.

The immune response to stroke is comprised of inflammatory and regulatory processes. One cell type involved in both innate and adaptive immunity is the dendritic cell (DC). A DC population residing in the healthy brain (bDC) was identified using a transgenic mouse expressing enhanced yellow fluorescent protein (EYFP) under the promoter for the DC marker, CD11c (CD11c/EYFP Tg).

The neuroprotective effect of prostaglandin E2 EP1 receptor inhibition has a wide therapeutic window, is sustained in time and is not sexually dimorphic.

We investigated the preclinical characteristics of the neuroprotective effect of the prostaglandin E2 type 1 receptor (EP1) antagonist SC51089 in models of focal cerebral ischemia produced by occlusion of the mouse middle cerebral artery (MCA). We found that systemic administration of SC51089 (5 to 20 microg/kg; i.p.

Nuclear factor-kappaB activation and postischemic inflammation are suppressed in CD36-null mice after middle cerebral artery occlusion.

CD36, a class-B scavenger receptor involved in multiple functions, including inflammatory signaling, may also contribute to ischemic brain injury through yet unidentified mechanisms. We investigated whether CD36 participates in the molecular events underlying the inflammatory reaction that accompanies cerebral ischemia and may contribute to the tissue damage. We found that activation of nuclear factor-kappaB, a transcription factor that coordinates postischemic gene expression, is attenuated in CD36-null mice subjected to middle cerebral artery occlusion.

Neurovascular protection by ischemic tolerance: role of nitric oxide and reactive oxygen species.

Cerebral ischemic preconditioning or tolerance is a powerful neuroprotective phenomenon by which a sublethal injurious stimulus renders the brain resistant to a subsequent damaging ischemic insult. We used lipopolysaccharide (LPS) as a preconditioning stimulus in a mouse model of middle cerebral artery occlusion (MCAO) to examine whether improvements in cerebrovascular function contribute to the protective effect. Administration of LPS 24 h before MCAO reduced the infarct by 68% and improved ischemic cerebral blood flow (CBF) by 114% in brain areas spared from infarction.

Cerebral pachyleptomeningitis associated with MPO-ANCA induced by PTU therapy.

A 34-year-old woman with hyperthyroidism, who had been previously treated with propylthiouracil (PTU) is reported. She was admitted because of clumsiness in her left hand and abnormal behavior. A neurological examination demonstrated impairment of higher cortical function, and weakness and hyperreflexia of the left leg.